Comparative Study of Two Different TiO2 Film Sensors on Response to H2 under UV Light and Room Temperature

An anatase TiO2film sensor was prepared by a facile in-situ method on the interdigitated Au electrode deposited on the alumina substrate. The structure, morphology and the optical properties of the in-situ TiO2film sensor were characterized by X-ray diffraction, Scanning Electron Microscopy, and UV-vis diffuse reflectance spectra. The photo-assisted gas sensitivities of the prepared film towards H2gas were evaluated at room temperature in N2and synthetic air atmospheres. As compared to TiO2film sensor prepared by drop-coating method, this in-situ TiO2film sensor exhibited a more compact structure composed of uniform TiO2microspheres as well as a better gas sensitivity towards H2under UV irradiation, especially in synthetic air. The photo-electrochemical measurements suggest that these improvements may be associated with the efficient charge transfer in the TiO2interface induced by the TiO2microsphere structure. This study might offer a feasible approach to develop photo-assisted gas sensors at ambient temperature.